US President Barack Obama has received the gold Nobel Peace Prize medal and diploma in a lavish ceremony in Norway.

Mr Obama accepted the prize with "deep gratitude and great humility" but warned that war was sometimes necessary despite its "acute" human tragedy.

In his speech at the ceremony, Mr Obama said the United States must uphold moral standards when waging wars that are necessary and justified.

He said violent conflict would not be eradicated "in our lifetimes", there would be times when nations would need to fight just wars and he would not stand idle in the face of threats to the American people.

"Where force is necessary, we have a moral and strategic interest in binding ourselves to certain rules of conduct," he said.

"And even as we confront a vicious adversary that abides by no rules, I believe that the United States of America must remain a standard bearer in the conduct of war."

Nine days after ordering 30,000 more US troops to Afghanistan to break the momentum of the Taliban, Mr Obama acknowledged the criticism of those who have said it was wrong and premature to award the Nobel accolade to a president still in his first year in office and escalating a major war.

He said America's adherence to moral standards, even in war, was what made it different from its enemies.

It was an embarrassment. Noble peace prize for sending more soldiers to die in a war for Israel. But that's okay because according to President Obongo it's totally justified because we are fighting "evil."

It's all over the blogs now that the Norwegians feel "dissed" and insulted by Mr. Obama as he has cancelled most of the events associated with the Nobel Prize, most importantly having canceled a luncheon with the Norwegian King.

And that's just so funny, because I was just so sure that Mr. Obama was going to bow down before King Harald V, or maybe it's just non-white royalty that he does that to??